The above-mentioned copending applications and disclosure documents relate to the depositing of material from a vapor phase on a substrate and are applicable to the coating of a wide variety of materials on a wide variety of substrates and particularly materials which have been difficult to apply heretofore in adherent coatings to substrates which have not generally been able to receive such coating without substantial alteration or various problems.
These documents in part have disclosed the coating of ceramics utilizing low-energy techniques with various coating materials including conductive layers so as to enable these ceramic bodies to be utilized in the semi-conductor industry and to permit terminals, conductors or circuit elements to be applied to the coated regions by soldering or other fusion techniques.
The basic principle underlying these earlier methods was the generation of the vapor by the striking of a low-voltage arc between two electrodes, one of which at least was vaporized to produce the vapor phase component which was deposited upon the substrate, contacted by vapor in a vacuum chamber. The vapor could be generated by striking the arc between a pool of metal and a counterelectrode under conditions disclosed in some of those applications, or by striking the arc between two electrodes without significant pool formation as disclosed in others of these applications, and these applications generally also describe the formation of compounds which are to be deposited upon substrates by reaction of material from one electrode with material from the other as the electrode materials are vaporized. The application also describe how compounds can be formed between a vaporized metal and a carrier gas which can be introduced into the region of the arc.
Notwithstanding the advances represented in these earlier applications, including the advances in the coating of ceramics, the problem of coating certain high-conductivity metals such as gold and silver, but most notably copper, upon ceramics in economical and highly adherent coating such that the conductive coatings can withstand the rigors of afterheating, e.g. heating during the application of conductive elements by soldering or other thermal fusion, has remained.